Work will continue on a project designed to describe the wall movements of the small bowel, the flows that they produce and the effect of such flows upon the transport of matter across the intestinal mucosa. The work will be mainly done in models, both descriptive and analytical models. BIBLIOGRAPHIC REFERENCES: Melville, J., Macagno, E.O., Christensen, J.: Longitudinal contractions in the duodenum: their fluid-mechanical function. Am. J. Physiol, 228: 1887-1892, 1975. Sancholuz, A., Croley, T. E., II, Christensen, J., Macagno, E. O., and Glover, J. R.: Phase lock of electrical slow waves and spike bursts in cat duodenum. Am. J. Physiol, 229: 608-612, 1975.